Fixes for Python particle API

crates/processing_pyo3/examples/flocking_duck.py

@@ -62,7 +62,7 @@ def setup():
     duck = gltf.geometry("LOD3spShape")
 
     p = create_particles(
-        geometry=duck,
+        duck,
         attributes=[
             Attribute.position(),
             Attribute.rotation(),

crates/processing_pyo3/examples/flocking_gpu.py

@@ -61,7 +61,7 @@ def setup():
     directional_light((0.95, 0.9, 0.85), 800.0)
 
     p = create_particles(
-        capacity=BOID_COUNT,
+        BOID_COUNT,
         attributes=[
             Attribute.position(),
             Attribute.rotation(),

crates/processing_pyo3/examples/particles_animated.py

@@ -23,7 +23,7 @@ def setup():
             for z in range(10):
                 positions.extend([x - 4.5, y - 4.5, z - 4.5])
 
-    p = create_particles(capacity=capacity, attributes=[Attribute.position()])
+    p = create_particles(capacity, attributes=[Attribute.position()])
     pos_buf = p.buffer("position")
     pos_buf.write(positions)
 

crates/processing_pyo3/examples/particles_basic.py

@@ -15,7 +15,7 @@ def setup():
 
     source = Geometry.sphere(5.0, 32, 24)
     p = create_particles(
-        geometry=source,
+        source,
         attributes=[Attribute.position(), Attribute.uv(), Attribute.color()],
     )
 

crates/processing_pyo3/examples/particles_density.py

@@ -18,7 +18,7 @@ def setup():
     mode_3d()
 
     p = create_particles(
-        capacity=N,
+        N,
         attributes=[
             Attribute.position(),
             Attribute.color(),

crates/processing_pyo3/examples/particles_emit.py

@@ -17,7 +17,7 @@ def setup():
 
     capacity = 2000
     p = create_particles(
-        capacity=capacity,
+        capacity,
         attributes=[Attribute.position(), Attribute.color()],
     )
 

crates/processing_pyo3/examples/particles_emit_gpu.py

@@ -29,7 +29,7 @@ def setup():
     # so declare them (all built-in here). `velocity`/`age` are built-ins now, so
     # no custom `Attribute(...)` is needed.
     p = create_particles(
-        capacity=CAPACITY,
+        CAPACITY,
         attributes=[
             Attribute.position(),
             Attribute.velocity(),

crates/processing_pyo3/examples/particles_from_mesh.py

@@ -15,7 +15,7 @@ def setup():
 
     source = Geometry.sphere(5.0, 32, 24)
     p = create_particles(
-        geometry=source,
+        source,
         attributes=[Attribute.position(), Attribute.uv(), Attribute.color()],
     )
 

crates/processing_pyo3/examples/particles_gpu_surface.py

@@ -14,7 +14,7 @@ def setup():
     window_title("gpu index")
     mode_3d()
 
-    p = create_particles(capacity=NX * NY, attributes=[Attribute.position()])
+    p = create_particles(NX * NY, attributes=[Attribute.position()])
     idx = p.index_buffer((NX - 1) * (NY - 1) * 6)
     gen = create_compute(load_shader("shaders/gen_surface.wesl"))
     gen.set(indices=idx)

crates/processing_pyo3/examples/particles_gpu_surface_lit.py

@@ -15,7 +15,7 @@ def setup():
     mode_3d()
 
     p = create_particles(
-        capacity=NX * NY,
+        NX * NY,
         attributes=[Attribute.position(), Attribute.color(), Attribute.normal()],
     )
     idx = p.index_buffer((NX - 1) * (NY - 1) * 6)

crates/processing_pyo3/examples/particles_lifecycle.py

@@ -22,7 +22,7 @@ def setup():
 
     capacity = 800
     p = create_particles(
-        capacity=capacity,
+        capacity,
         attributes=[
             Attribute.position(),
             Attribute.color(),

crates/processing_pyo3/examples/particles_lines.py

@@ -23,7 +23,7 @@ def setup():
     mode_3d()
 
     p = create_particles(
-        capacity=N,
+        N,
         attributes=[Attribute.position()],
     )
     p.buffer("position").write([list(knot(i / N * tau, 0.0)) for i in range(N)])

crates/processing_pyo3/examples/particles_lissajous.py

@@ -34,10 +34,10 @@ def setup():
     window_title(f"Lissajous — all points connected — {N:,} pts")
     mode_3d()
 
-    p = create_particles(capacity=N, attributes=[Attribute.position(), Attribute.color()])
+    p = create_particles(N, attributes=[Attribute.position(), Attribute.color()])
     # One line = 2 vertices; up to N*MAX_LINKS lines.
     edges = create_particles(
-        capacity=N * MAX_LINKS * 2, attributes=[Attribute.position(), Attribute.color()]
+        N * MAX_LINKS * 2, attributes=[Attribute.position(), Attribute.color()]
     )
     idx = edges.index_buffer(N * MAX_LINKS * 2)  # link fills indices + the dynamic count
 

crates/processing_pyo3/examples/particles_noise.py

@@ -16,7 +16,7 @@ def setup():
 
     source = Geometry.sphere(5.0, 32, 24)
     p = create_particles(
-        geometry=source,
+        source,
         attributes=[Attribute.position(), Attribute.uv(), Attribute.color()],
     )
 

crates/processing_pyo3/examples/particles_plexus.py

@@ -25,7 +25,7 @@ def setup():
     mode_3d()
 
     p = create_particles(
-        capacity=N,
+        N,
         attributes=[Attribute.position(), Attribute.velocity(), Attribute.color()],
     )
 

crates/processing_pyo3/examples/particles_points.py

@@ -15,7 +15,7 @@ def setup():
     mode_3d()
 
     p = create_particles(
-        capacity=COUNT,
+        COUNT,
         attributes=[Attribute.position()],
     )
 

crates/processing_pyo3/examples/particles_scatter_volume.py

@@ -26,7 +26,7 @@ def setup():
     particle = Geometry.sphere(0.15, 4, 3)
 
     p = create_particles(
-        capacity=CAPACITY,
+        CAPACITY,
         attributes=[
             Attribute.position(),
             Attribute.scale(),
@@ -45,7 +45,7 @@ def draw():
     seed = (int(elapsed_time * 1000.0) ^ 0xC0FFEE) & 0xFFFFFFFF
     scatter.set(seed=seed)
     p.emit_gpu(BURST, scatter)
-    p.apply(MAP, a="scale", op=AFFINE, scale=0.985, offset=0.0)
+    p.apply(MAP, "scale", op=AFFINE, scale=0.985, offset=0.0)
 
 
 run()

crates/processing_pyo3/examples/particles_sphere.py

@@ -16,13 +16,13 @@ def setup():
     rest = Attribute("rest", AttributeFormat.Float3)
     sphere = Geometry.sphere(1.5, 96, 64)
     p = create_particles(
-        geometry=sphere,
+        sphere,
         attributes=[
             Attribute.position(),
             rest,
         ],
     )
-    p.apply(MAP, a=Attribute.position(), out=rest, op=AFFINE, scale=1.0, offset=0.0)
+    p.apply(MAP, Attribute.position(), out=rest, op=AFFINE, scale=1.0, offset=0.0)
 
 
 def draw():

crates/processing_pyo3/examples/particles_stress.py

@@ -25,7 +25,7 @@ def setup():
     directional_light((0.0, 0.0, 1.0), 1000.0, position=Vec3.Z, look_at=Vec3.ZERO)
 
     p = create_particles(
-        geometry=Geometry.grid(GRID, GRID, GRID, SPACING),
+        Geometry.grid(GRID, GRID, GRID, SPACING),
         attributes=[Attribute.position(), Attribute.uv(), Attribute.color()],
     )
 

crates/processing_pyo3/examples/particles_surface.py

@@ -30,7 +30,7 @@ def setup():
     window_title(f"Particle surface — {N:,}-vertex Mobius strip")
     mode_3d()
 
-    p = create_particles(capacity=N, attributes=[Attribute.position()])
+    p = create_particles(N, attributes=[Attribute.position()])
 
 
 def draw():

crates/processing_pyo3/src/graphics.rs

@@ -800,8 +800,7 @@ impl Geometry {
         Ok(Self { entity })
     }
 
-    /// lattice centered at the origin; topology is `POINTS`, intended as a
-    /// position source for `Particles(geometry=...)` rather than rasterized.
+    /// A point lattice centered at the origin, to seed `create_particles(geometry)`.
     #[staticmethod]
     #[pyo3(signature = (nx, ny, nz, spacing=1.0))]
     pub fn grid(nx: u32, ny: u32, nz: u32, spacing: f32) -> PyResult<Self> {

crates/processing_pyo3/src/lib.rs

@@ -1626,18 +1626,15 @@ pub mod mewnala {
         Ok(window)
     }
 
-    /// Creates a GPU particle system (Processing `createParticles`). `attributes`
-    /// defaults to `position`; other built-in attributes (`velocity`, `color`,
-    /// `scale`, `life`, `age`, ...) and declared custom ones materialize on
-    /// demand when you call `buffer("name")`.
+    /// Creates a GPU particle system (Processing `createParticles`) from a count or a `Geometry`.
+    /// Attributes are created on first use.
     #[pyfunction]
-    #[pyo3(signature = (capacity=None, attributes=None, geometry=None))]
+    #[pyo3(signature = (source, attributes=None))]
     fn create_particles(
-        capacity: Option<u32>,
+        source: &Bound<'_, PyAny>,
         attributes: Option<Vec<PyRef<'_, super::particles::Attribute>>>,
-        geometry: Option<&Geometry>,
     ) -> PyResult<super::particles::Particles> {
-        super::particles::Particles::create(capacity, attributes, geometry)
+        super::particles::Particles::create(source, attributes)
     }
 
     /// Creates a compute pass from a shader (Processing-style `createCompute`).